Various control circuits for accurately regulating boiling or cooking temperature without allowing it to exceed a preselected boiling or cooking temperature are known. Value is often placed on achieving the desired boiling or cooking temperature as rapidly as possible in the warm-up phase and steps are taken to assure that this initial heating phase requires a minimum of energy.
These known control circuits also have enough accuracy in their control so that it is possible to select a cooking temperature near the boiling point of water without significant evolution of steam. However, with such known control circuits, this accuracy cannot always be fully utilized, because the dependence of the boiling point of water on the geographic altitude at the place of use has the effect of interfering, especially with the temperature range near the boiling point of water.